Protesters march in silence down Market Street in St. Louis on Monday in response to a not-guilty verdict in the trial of a former St. Louis police officer. (Cristina Fletes/St. Louis Post-Dispatch via AP)

More protests planned Tuesday in St. Louis

A judge had found a white former police officer not guilty in the shooting death of a black man.

ST. LOUIS — Protesters chanting “free our people” gathered outside the jail in downtown St. Louis for more than two hours Monday night to show solidarity with those who remain behind bars.

Police said more than 120 people were arrested during Sunday’s protests over the acquittal of a white former police officer in the killing of a black suspect. Demonstrators outside the jail criticized authorities for keeping some of those arrested in jail nearly 24 hours after they were taken into custody.

“That was the main purpose of the night. To be in solidarity,” said Cheyenne Green, 24, of St. Louis, who helped organize Monday evening’s event and others since Friday’s verdict.

Some of those jailed were released Monday evening before organizers announced an end to the demonstration and told people to go home. Organizers said protests will resume Tuesday, but they gave no details.

Monday was the fourth day of protests. In the morning, a racially mixed crowd of demonstrators marched through downtown.

The latest action follows three days of peaceful protests and three nights of vandalism and unrest in the city that’s been rocked since Friday, when a judge announced he found Jason Stockley not guilty in the 2011 death of Anthony Lamar Smith.

Smith’s mother, Anne Smith, was among those gathered outside the downtown jail on Monday.

Hundreds of riot police mobilized downtown late Sunday, arresting more than 80 people at one intersection who police said didn’t follow orders to disperse. Earlier, police had responded to reports of property damage and vandalism.

“I’m proud to tell you the city of St. Louis is safe and the police owned tonight,” Interim Police Chief Lawrence O’Toole said at a news conference early Monday.

But Sean Porter, 25, of St. Louis, was among those arrested at the intersection and one of several who said Monday that they could not follow orders to disperse because police had them blocked in.

“They threw us on the ground, sprayed us, hit us, everything. It’s tragic,” said Porter, who was released from jail Monday evening. He was charged with failure to disperse.

The St. Louis Post-Dispatch reported that reporter Mike Faulk, who was on the street reporting about the protests, had an experience similar to the one Porter described.

Police blocked all four sides of the intersection. Faulk heard the police command to move back, but he had nowhere to go, the newspaper said. Multiple officers knocked Faulk down, he told the Post-Dispatch, and pinned his limbs to the ground. A foot pushed his head into the pavement and he was squirted with pepper spray after he was subdued, he said.

Protesters marched through St. Louis’ posh Central West End and the trendy Delmar Loop area of nearby University City on Friday and Saturday. Protesters also marched through two shopping malls in a wealthy area of St. Louis County.

On Sunday, more than 1,000 people had gathered at police headquarters and then marched without trouble through downtown St. Louis. By nightfall, most had gone home.

But the 100 or so people who remained grew increasingly agitated as they marched back toward downtown. Along the way, they knocked over planters, broke windows at a few shops and hotels, and scattered plastic chairs at an outdoor venue.

According to police, the demonstrators then sprayed bottles with an unknown substance on officers. One officer suffered a leg injury and was taken to a hospital. His condition wasn’t known.

Soon afterward, buses brought in additional officers in riot gear, and police scoured downtown deep into the night, making arrests and seizing at least five weapons, according to O’Toole. Later, officers in riot gear gathered alongside a city boulevard chanting “whose street, our street” — a common refrain used by the protesters — after clearing the street of demonstrators and onlookers.

“We’re in control. This is our city and we’re going to protect it,” O’Toole said.

Mayor Lyda Krewson said at the same Monday news conference that “the days have been calm and the nights have been destructive” and that “destruction cannot be tolerated.”

Early Monday, more than 150 protesters marched arm-in-arm, some carrying signs, to city hall. Police turned traffic away as the marchers blocked a busy St. Louis street during the rush hour crush. Once at city hall, they found their voices, chanting: “I know that we will win.” The protesters then marched four blocks to a city court building, where they chanted again, then dispersed.

Also Monday, high school students in at least two suburban districts protested the Stockley ruling. In Kirkwood, about 100 students walked out and held a brief rally, while 250 students in Webster Groves staged what school officials described as a peaceful demonstration.

The recent St. Louis protests follow a pattern seen since the August 2014 killing of Michael Brown in nearby Ferguson: The majority of demonstrators, though angry, are law-abiding. But as the night wears on, a subsection emerges, a different crowd more willing to confront police, sometimes to the point of clashes.

Protest organizer Anthony Bell said he understands why some act out: While change can come through peaceful protests, such as those led by Dr. Martin Luther King Jr., years of oppression has caused some to turn violent.

“I do not say the (unruly) demonstrators are wrong, but I believe peaceful demonstrations are the best,” Bell said.

Many protesters believe police provoked demonstrators by showing up in riot gear and armored vehicles; police said they had no choice but to protect themselves once protesters started throwing things at them.

Stockley shot Smith after high-speed chase as officers tried to arrest Smith and his partner in a suspected drug deal.

Stockley, 36, testified he felt endangered because he saw Smith holding a silver revolver when Smith backed his car toward the officers and sped away.

Prosecutors said Stockley planted a gun in Smith’s car after the shooting. The officer’s DNA was on the weapon but Smith’s wasn’t. Dashcam video from Stockley’s cruiser recorded him saying he was “going to kill this (expletive).” Less than a minute later, he shot Smith five times.

Stockley’s lawyer dismissed the comment as “human emotions” during a dangerous pursuit. St. Louis Circuit Judge Timothy Wilson, who said prosecutors didn’t prove beyond a reasonable doubt that Stockley murdered Smith, said the statement could be ambiguous.

Stockley left the police department and moved to Houston three years ago.

A man throws a rock into the window as demonstrators march on Sunday in St. Louis in response to a not-guilty finding in the trial of a former St. Louis police officer. (AP Photo/Jeff Roberson)

Demonstrators participate in a “die-in” outside the St. Louis Police Department headquarters on Sunday in response to a not-guilty finding in the trial of a former St. Louis police officer. (AP Photo/Jeff Roberson)